Re-target for ES.Next (#3901)

A list of changes:
- 'es2015-subset' profile is deprecated, and an 'es.next' profile is added.
- The default profile is changed to 'es.next'
- Renamed the JERRY_ES2015 guard to JERRY_ESNEXT
- Renamed JERRY_ES2015_BUILTIN_* guards to JERRY_BUILTIN_*
- Moved es2015 specific tests to a new 'es.next' subdirectory
- Updated docs, targets, and test runners to reflect these changes

Resolves #3737.

JerryScript-DCO-1.0-Signed-off-by: Dániel Bátyai dbatyai@inf.u-szeged.hu

jerry-core/ecma/builtin-objects/ecma-builtin-generator.inc.h

@@ -19,7 +19,7 @@
 
 #include "ecma-builtin-helpers-macro-defines.inc.h"
 
-#if ENABLED (JERRY_ES2015)
+#if ENABLED (JERRY_ESNEXT)
 
 /* ECMA-262 v6, 25.3.2.3.1 */
 OBJECT_VALUE (LIT_MAGIC_STRING_CONSTRUCTOR,
@@ -36,6 +36,6 @@ STRING_VALUE (LIT_GLOBAL_SYMBOL_TO_STRING_TAG,
               LIT_MAGIC_STRING_GENERATOR_FUNCTION_UL,
               ECMA_PROPERTY_FLAG_CONFIGURABLE)
 
-#endif /* ENABLED (JERRY_ES2015) */
+#endif /* ENABLED (JERRY_ESNEXT) */
 
 #include "ecma-builtin-helpers-macro-undefs.inc.h"